Law AgreementsIllinois Child Support Calculator
Calculate estimated child support using Illinois' Income Shares model. Illinois considers both parents' net incomes and adjusts for shared parenting time when the non-custodial parent has more than 146 overnights per year.
Basic Info
Your Role
Select your role in this custody arrangement.
Children
Estimated Monthly Support
$0/month
Payable by: Non-Custodial Parent
Calculation Breakdown
Important Disclaimers:
- This is an estimate only based on standard state guidelines
- Actual support is determined by the court
- Judges have discretion to deviate from guidelines
- Does not account for all possible factors
Why Use Our Illinois Calculator?
How Illinois Calculates Child Support
Illinois adopted the Income Shares model in 2017, replacing its previous Percentage of Income approach. The calculation starts by determining each parent's net income (gross income minus taxes, mandatory retirement contributions, and certain deductions). The parents' net incomes are combined, and the Illinois schedule of basic child support obligations determines the basic support need based on the combined income and number of children. Each parent is responsible for their proportionate share. The non-custodial parent's share becomes the child support obligation, subject to adjustments for parenting time, healthcare, childcare, and other expenses.
Illinois Shared Parenting Adjustment
Illinois provides a significant adjustment when parents share parenting time roughly equally. When the non-custodial parent has 146 or more overnight stays per year, the shared parenting formula applies. This formula multiplies the basic obligation by 1.5, then assigns each parent's share based on their income percentage. Each parent's obligation is then adjusted by the percentage of time they spend with the child, and the parent with the larger obligation pays the difference to the other parent. This recognizes that both parents incur direct child-related expenses during their parenting time.
Modifying Child Support in Illinois
Illinois child support orders can be modified when there is a substantial change in circumstances. This includes significant changes in either parent's income, changes in the child's needs, changes in parenting time, or changes in healthcare or childcare costs. Additionally, either parent can request a review every three years, or at any time if the existing order differs by 20% or more from what the current guidelines would produce. Modifications take effect from the date of filing, not retroactively.
Other State Calculators
Texas Child Support Calculator
Calculate estimated child support payments using the Texas Percentage of Income guidelines. Texas applies a flat percentage to the non-custodial parent's net resources based on the number of children.
Florida Child Support Calculator
Calculate estimated child support payments using Florida's Income Shares model. Florida considers both parents' incomes, the number of overnight stays, and additional child-related expenses.
California Child Support Calculator
Calculate estimated child support using California's complex algebraic guideline formula. California considers both parents' net disposable incomes, the percentage of time each parent has custody, and additional child-related expenses.
Ohio Child Support Calculator
Calculate estimated child support using Ohio's Income Shares model. Ohio considers both parents' gross incomes, the basic child support schedule, and adjustments for healthcare, childcare, and parenting time.
Frequently Asked Questions
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